Heating and work handling apparatus



July 22, 1952 H. A. STRICKLAND, JR, ET AL HEATING AND WORK HANDLING APPARATUS 3 Sheets-Sheet 1 Filed Dec. 6, 1947 Q 0N; a .1 I r 9 Q5 I INVENTORS. Harold AStnckiandJr.

Donaid W [QLddel 1.

r omwsy y 1952 H. A. STRICKLAND, JR., EI'AL 7 HEATING AND WORK HANDLING APPARATUS Filed Dec. 6, 1947 3 Sheets-Sheet 2 I N VEN TORS Harold Q. Stnckland Jr 0mm wmdeli.

ATTORNEY 7 H. A. STRICKLAND, JR., ETAL 2,604,577

HEATING AND WORK HANDLING APPARATUS July 22, 1952 Filed DeC. 6, 1947 3 Sheets-Sheet Z5 F90 ImDa 1NVENTOR$ v Harbld Q. Sfi LcRlandJr.

Donqld W R'Lddel ATTORNEY TNNC.

Patented July 22, 1952 HEATING AND WORK HANDLING APPARATUS Harold A. Strickland, Jr., Grosse Pointe Park, and Donald W. Riddell, Detroit, Mich., assignors, by mesne assignments, to The Ohio Crankshaft Company, Cleveland, Ohio, a corporation of Ohio Application December 6, 1947, Serial No. 790354 3 Claims.

This invention. relates to heating and work handling apparatus, particularly to induction heating apparatus, and has for an object the provision of improvements in this art.

One of the particular objects of the invention is to provide apparatus which will feed a workpiece or billet into a furnace, time its heating. period, eject it backward. from the furnace, remove it and bring up a new workpiece for feeding, all in a controlledandautomatic manner.

Another, object isto provide a feeding device which will push a workpiece into the furnace and cause a heating cycle to be initiated but which with-drawsbeforethe workpiece becomes heated so as to avoid injury to the feeding device.

Another object is to provide a push-out or ejector device whichv can be operated either by a timer or manuallyand which, when operated, pushes out the workpiece, to a position where it clears the front of the furnace but with the push-out element in a position to clear certain side transfer means in front of the furnace.

Another object is; to provide that each part is fully operated and clear before the next succeedingpart'is operated. a

The above and-other objects and advantages of the invention will be apparent from the following description of an exemplary embodiment, reference being made tothe accompanying drawings wherein: v a v Figure 1 is a pictorial view, looking at a side and end, showing an embodiment in which an induction heating furnace heats billets or workpieces throughout their entire length;

Figure 2 i's-an end elevation of transfer mechanism and related apparatus;

Figure 3 is aview of: the parts. shown in Fig. 2 but in a different position;

Figure 4 is a view similar to Figs. 2 andv 3 but with the parts shown in another" position;

and I Figure dis a wiring; diagram with operating parts shown schematically. 1

Referring to the drawings; a heatingfurnace I" is provided with an axially elongated heating chamber Htoreceive and heat a; workpiece or billet 12'." In the'present" embodiment, an induction heating furnace having a fluid-cooled heating coil [3 is used. Thisz-furnace may be of the type and may be mounted, asshown in the patent to ,Strickland,.2,408,350, granted September 2.4, 1946. Thecoi-llhood, closure panels or doors fortheframe; pressure. and cooling fluid supply means with pressure-assuring and heatlimiting means thereforroi the patent may l 2 be used herein, although for simplicity they are omitted from the apparatus views and shown only in the schematic view, Fig. 5.

Means are provided for pushing a workpiece into the furnace, the means here shown comprising a push-bar, ram or plunger I5 carried by a cross head l6 which is slidable on a guide bar 11. The push-bar i5 is, adjustable in a projection is of the crosshead and is held in adjusted positions by' a set screw IS. A link 20 is connected to the crosshead by a pin 2| and the link is connected by a pin 22 to a power arm 23 mounted by a pin 24 to a, fixed support 25.

The arm 23 is actuated by reciprocating power means, here including a piston 26 (Fig. 5) operating in a cylinder 21 and having the piston rod 28 connected to the arm 23 by a forkfZBanda pin 30. The lever and linkage connectionprovides a quick feed and reduces" floor space but, of course, if desired, a direct action piston pusher may be used, or any other suitable type of pushin mechanism. Pressure fluid is supplied to and exhausted from the headland rod ends of the cylinder by pipes 3| and 32 respectively.

In the present illustration, the workpiece wholly enters the furnace but the same type of mechanism is used for long workpieces where only an end enters the furnace. I

Means are provided for pushing a workpiece rearwardly out of the furnace, the means here shown comprising a push-bar, ram of plunger 35, formed as a piston rod or extension thereof of a push-out piston 33 operating in a cylinder 31. Pressure fluid is supplied to the head end of the cylinder by a pipe 38. The piston rod. or extension 35 operates in a tubular guide 39' adjustably mounted in a support 49 carried by the cylinder 31. The front end'of the guide tube 39 forms a limit stop for workpieces pushed into the furnace. Atits rear position, the push bar 35 would form a limit stop if the tube did not.

Means are provided for removing a. heated workpiece when pushed-out of the furnace and for bringing a new workpiece into feedingposition, the means here shown comprising a V- shaped guide and support trough 45 .turnably mounted on. a rock shaft 46. The. V-trough is power operatedto swing down to transfer a hot workpiece'to a deliverytable 41 and to swing from a chute 48 which is long enough to hold a considerable number of workpieces. Escapement means in the form of dogs 49 and 56 are provided for feeding workpieces from the chute into the trough, the dogs 49 feeding to dogs 50 which hold a workpiece while the trough is turned to dumping position; and the dogs 50 feeding a single workpiece to the trough when it is returned to upright position while the dogs 49 hold back the stack of workpieces in the chute.

Power means are provided for operating the V-trough and the escapement dogs, the power means here shown comprising a transfer piston 52 operating in a cylinder 53 and having its piston rod 54 connected by a fork 55 and a pin 56 with an arm 51 secured on the shaft 46 of the trough. Pressure fluid is supplied to the head and rod ends of the cylinder 53 by pipes 58 and 59 respectively.

The dogs 49 and 56 are arranged in pairs, the dogs 49 being carried by rock levers 6| and the dogs 50 being carried by rock levers 62, both sets of rock levers being turnably mounted on a fixed shaft 63. At their upper ends the levers 6| and 62 are provided with cam rollers 64, 65 respectively which ride on operating earns 66 and 61 respectively which are secured on a cam rock shaft 68 turnably mounted in a suitable frame. Most of the frame is omitted for clarity, the anchorages therein only being shown by section lines.

The rock shaft 68 is provided with an arm 69 to which a connecting rod or link 16 is attached.

The operation of the apparatus may now be explained by reference to the mechanisms which have been shown in Figs. 1 to 4 and described hereinabove and by particular reference to the schematic mechanism and wiring diagram, Fig. 5.

As a reference point, it will be assumed that the push-out piston 36 is in its forward position (where it remains unless pushed back by the push-in piston), that the push-in iston 26 is in its rearward position, having moved back shortly after it pushed in the last previous workpiece, and that the transfer piston 52 is in its rear position (in this case, because of the lever system, it is actually at the rod end of its cylinder). Also, it is to be noted that there is a device which may be designated as a load switch operator LS, associated with the push-out bar or ram 35, which is actuated by a cam surface 86 on the bar when the bar is in its rearmost position. In the forward position of the push-out bar a load switch LS-2 stands closed and a load switch LS-l stands open, but when the bar reaches its rearmost position switch LS-l is closed and LS-2 opened to change again as soon as the bar starts forward. Another associated device, which may be designated as an air cylinder switch AS-| of a cam operated device AS, stands closed except when the push-out bar is in its most forward position, being there opened by a cam 8| on the push bar.

The transfer piston 52 has associated with it a switch TS-l which stands closed when the transfer piston is in its retracted position (here at the rod end, as stated) but which opens as soon as the piston starts forward and closes again as the piston reaches the end of its return stroke. The operating device is actually an oscillating cam TS but for purposes of illustration, a lateral projection is shown in Fig. 5 and designated by the same character as the cam. Also, in Fig. 5 the transfer mechanism is treated as comprising a flat table across which workpieces are pushed by a piston which has a stroke of a length just equal to the width of a workpiece, the heated workpiece after return being pushed away down an incline and a new workpiece placed on the table near the transfer piston.

To prepare for the start of operations, a main switch S| is closed in the main current supply lines Ll, L2. This lights a lamp 83.

Water is supplied to the induction heating coil and when this reaches the proper pressure, a pressure switch PS in L2 is closed. A lamp 84 indicates closure of the pressure switch. Thermostat switches H-|, H4 in L2 open only if the coil or cooling water therefor become too hot, so they will be considered to be closed under all normal conditions. An emergency stop push button PB-l in L2, when pressed, will halt all operations but it normally stands closed, as shown.

To start operations, the operator presses start push button PB-2. Thisenergizes a solenoid S03 which actuates a valve.V3 of the push-out cylinder 31, but as the piston is already in forward position, no action occurs here. Closure of start push button PB-Z also energizes a relay which has a time delay action in part and is designated as auto start push-out TR2.

The paths established by closure of PB-Z are as follows. For S03, from LI current flows through LB| through a safe run switch 8-2, which is normally closed, to S03, thence by conductor 85 to a stop push button switch P133, through its normally closed contacts PB3-I and conductors 86, 81 to PB-Z (start), through its contacts (momentarily closed) and a conductor LE2 toLZ.

For TR2, from LB| current flows through conductor 88 to the coil of TR2 (here represented as two coils for simplicity, one for a time delay drop-off switch TR2-| and the other for a quick action operator for switches TR2-2 and TR2-3), thence through conductors 89, 90 and 81 to P34 and from this through L132 to L2.

Time relay TR2, when energized, opens the normally closed switch TR2-2 and closes switch TR2-3. It also closes time delay switch TR2-|. The schematic illustration indicates that the time delay is causedby a dash-pot action, the switch blade remaining in a closed or open position until moved by lugs on its dash-pot operated rod.

Closure of TR2-3 has no immediate effect because at this time air cylinder switch AS-I, which is in series with it, is open. (Circuit, LB|, coil 'I'R2, conductor- 92. TR2-3, 93, AS-l and conductor 94 to L2 beyond PB-l.)

Closure of time delay switch TRZ-l will have no immediate effect because quick-close switch TRZ-Zis in circuit with it and this is open and remains open as long as PB-2 is closed. However, as soon as PB-2 is opened, it deenergizes TRZ and TR2-2 closes at once. Since TR2| remains closed for a delay action period, another delay action transfer timer relay TRI is energized. (Circuit, LB|, conductorv 95, conductor 96, coil TRI, conductorlll, TRZ-I, TR2-2, conductor 98, conductor 99, conductor I00, conductor lfll, load switch LS-2 (now closed because push-out eme ges? piston 36 is forward), I02, I03, 94,'-to L2 beyond It may here be noted that a safety' relay is put in circuit beyond the pressure switch PS, overheat switches H-I I-I-2 and emergency stop push button PB-I. This may be designated as an anti-reset relay ARR. If the push-out piston is forward, ARR is energized assoon' as current is established through PB-I. (Circuit,-LI, conductor I05, coilof ARR (pilot lamp 'I06 in parallel), IOI, LS-2, I02, I03, 94 to L2 beyond PB-I.) When ARR is energized, it closes its lockswitch ARR-2. (Circuit, LI, I05, coil of ARR, conductor I0'I, ARR-2to L2.) It also closes its switch ARR-I, which is in series with load switch LS-I, to close a gap in L2 beforeheat can'be'supplied. to the heating coil; (Circuit, L2, 94, I03, LS-I, conductor I09, ARR-I, L2.)

When TRI is energized, it closes its delay switch TRI-I and opens its quick-action switch TRI-2. As soon as TR2-I opens, it deenerglzes TRI and its switch TRI-2 will close at once but TRI-I will remain closed for a time. This causes a relay, which may be designated as a transfer pilot relay, TPR, to be energized to close its switch TPR-I. (Circuit, LBI, 95, conductor H0, TPR, conductor III, TRI-I, conductor II2, TRI-2, I00, I9I, LS-2, I02, I03, 94 to L2 beyond PB-I.)

Closure of the switch TPR-I of'TPR energizes the solenoid SOI of a valve VI of the transfer cylinder 53. (Circuit, LBI, 95, conductor II3, coil of SOI, conductor II4, TPR-I, conductor II5, conductor Hi to L132.)

Transfer piston 52 moves out to remove a hot workpiece (if present) and raise feed-down do 49 to allow the stack of workpieces in the chute to move down against the holding dog 50. In Fig. 5, as stated, the escapement action is omitted and. the action dealt with as if the piston 52 pushed the line of workpieces across a table until the hot one dropped off and another was brought into feeding position. As soon as the piston 52 starts to move out, it operates its switch actuator TS, and causes its switch TS-I to be closed; This energizes a thirddelay-action relay TR3 associated with the push-in piston. (Circuit, LBI, 95, conductor I2l, coil of 'I'R3, conductor I22, switch TSI conductor I23, 98, 99, I00, IOI, LS-2, I02, I03, 94 to L2 beyond PBP-I.)

When TR3 is energized, it I closes its delayaction switch TR3-I and opens its quick-action switch TR3-2. There is no immediate effect from this switch actuation.

Shortly, however, time delay switch TRI-I opens, which deenergizes SCI and transferpiston 52 moves back. In this'movement, it turns the V-trough to. an upright position and'causes the upper dogs 49 to be'lowered to hold the line of workpieces above the lowermost one and also causes the lower dogs 50 to release a workpiece to drop into the v-trough.

As the transfer piston 52 completes its return stroke, it opens its switch TS-I, which causes TR3 to be deenergized. Its switch TR3-2 closesat once but its time delay switch TR3-I remains closed for a while. This causes a push-in pilot relay PPR to be energized. (Circuit, LB-I, e5, coil PPR, conductor I25, TR3--I, conductor I26, TR3-2, conductor I21, 98,99, I00, IOI, LS-2', I02, I03, 94 to L2 beyond PB-I.)

Energization of PPR causes its normally open switch PPR-I to be closed. Closure of PPR-I energizes solenoid S02to actuate the valve.V2 of the push-in cylinder 21. (Circuit; LBI, 95-,

' machine'whichthe present apparatus serves.

the main contactor relay CR.

'6 conductor I28,--coli -SO2, conductor I29, PPR-I, I I6-to L132.)

Push-in piston 26 moves fo'rward.--A- workpiece whiohis-in trough 45 is pushed into the furnace until its end comes against the frontend of the adjustable tubular guide 39.

The push-out piston 36 is pushed baCk.--'At the start of its-rearward movement, piston 36, through cam 8|, causes, switch AS-I to be closed and atwthe completion of its rearward stroke, through cam 80,-causes switch LS-I to beclosed and1LS-.2 to beopened. I

. After its time delay period, switchTRt-I drops to deenergize PPR and S02 and allow valve V2 to, change itspositiom I Push-inpiston 26 returns-Thishas no effect on any of the-interlocking meansv but gets the push bar back out of'the furnaceso it will not be heated. Itdoes not necessarily have to. re-

turn .bef ore the heating period begins.

remains energized untilsome abnormal eventoccurs.

Closure of. load switch; LS-I beginsa sequence of' actions which. ends'with theapplication of heat and theinitiationof a timin period, It is in'series withswitch ARR-I to-close a gap in L2 but since ARR normally maintains ARR-I closed, the control of thisphase of-action, is left to. LS-I alone. Closure-of LS-J- causes a, timer control-pilot. relay ICE; to .be energized: (Circuit, LI, conductor I132, coil TCR, (lampr I33 in parallel) conductor I34, normally closed switch CR-3' of a main contactonrelayCR, conductor I to L2.) Energization of relay TCR and closure of its switch TCR-I. places a sequence controller SC and timing; devices *TI, T2 (in parallel) in :connection with L2. The sequence controller is timed to the action of some forging might as well time thevoperation of the present apparatus with that Of a similar heating apparatus. It need not be described. (Circuit, L2, conductor I31, TCR-I, conductorv I38, SC, conductor, I39, conductor I-40a, I40b', clutch coils TI-C,T2-C of TI, T2, conductors I4Ia, I4 Ib, conductor I42, conductor I43 to LI.)

Closure of ARR-I also puts current on the motors TI-M, T2-M of the timers, switches TI-I, T2-I being at this time. closed. (Circuit, T2, conductor I45, conductors 146a, I46b, switches TI-I, T2-.I, motors TI-M, T2-M, I4Ia, I4), I42, I43 to LI.)

Closure of ARR-I also energizes timer relays TI-R, T2-R to close switches TI-RI, T2-RI in L2. (Circuits, L2 I45, I46a, I461), switches TI-I, T2-I, conductors I410, I411), coils TI-R, TZ-R, conductorsl40a, I4Bb to LI.) It is to be understood'that the furnacecasing door switches DS are-closed, that the'cooling-fluid flow switch FS is closed, and the heatingcoil hoodswitch HS is closed to complete L2 to T I RI and T2 -RI.

Closure of switches TI-Rl and T2-RI energizes (Circuit, L2, conductor I49, coil of CR (lamp I50 in parallel),

I conductor I5I to LI.)

Closure of switches vCR-I, CR-4 and CR-Z energizes the rectifier circuits generally indicated at RCI, RC2 to energize main'contactor coil terminals RCI-T, RCZ-T to supply high frequency heating current from another supply circuit to line conductors I-lLI, HLZ to heating coil I3.

Heating period begins Opening of switch CR-3 deenergizes TCR. and opens TCR-I which, in turn, deenergizestimer clutch coils TI-C, TZ-C to engage the clutches with the motor shafts to start the timing action contemporaneously with the start of the heating action.

It may here be noted that the timers TI', T2 are of the type having a fixed contact hand settable for a given period, a movable contact hand which is spring-returned to zero when the clutch is released and which is driven around to the fixed hand when the clutch is reengaged. A synchronous drive motor is employed for the clutch shaft of the movable-hand. I

The use of two timers is for the purpose of assuring that at least one will operate properly, for greater safety.

At the completion of a timing period, or when the timer first to completeits action closes its circuit, the auto start relay IE2 is energized. (Circuit, L2, I45, I 4I5a, I45b, conductors I53a, I53b, timer finish switches TI-Z, T2-2, conductors I54a, I541), conductor I55, 89, coil of TR2, 88 to LBI.) A lamp I56 is in parallel to show completion of the timing cycle and heating period.

Energization of 'IRZ closes TRZ-I, opens TR2-2 and closes TR2-3. TR2-3 is in series with air cylinder switch AS-I, which remains closed until the piston 36 reaches the forward end of its stroke. S03 is thereby energized. (Circuit, LBI, 88, coil TRZ, 92, TR2-3, S3, AS-I, 24 to L2.) This has the same effect as if start push button PB-2 had been pushed.

Push-out piston 36' moves forwardJ-This action, through its push bar 35, pushes a heated billet from the furnace and upon the V-trough. The bar 35 does not advance far enough to foul the turning action of the trough.

At the start of its forward movement, the push-out piston opens load switch LS-I in L2 to stop the timers, by deenergizing TCR, and to cut current from the heating coil by deenergizing CR. (Heatingperiod ends). The push-out piston movement also closes its load switch LS2 but, as seen, the operation of this switch has no effect as long as anti-reset relay ARR is locked in through ARR-2. At the extreme forward end of its movement, piston 36 opens air cylinder switch AS-I to deenergize TRZ and S03.

From here on the cycle of operations previously described is repeated, that is, the automatic actions which were initiated by the deenergization of TR2, as previously described to be caused by release of the push button PB-Z, are started, the transfer piston being operated back and forth to transfer the hot workpiece and feed in a new one, the push-in piston moving the workpiece into the furnace and pushing the push-out piston back, and so forth.

If the stopi-push button PB3 is pushed down, it opens PB3-I and closes PB3-2 which causes V the push-out-piston to at once eject a workpiece from the furnace. v

If the top push button PB-I in L2 is pushed down, the anti-reset relay ARR. is deenergized and all operations are stopped. e 7

From the above description and a careful consideration of the wiring diagram, it will be noted down a new workpiece. Even if a cold workpiece is in the trough at the start, it will be transferred and a new workpiece fed in. This insures against reheating and thus overheating a partially heated workpiece. It also insures that the V-trough will always be clear'for the reception of 'a workpiece pushed back out of the furnace.

It will thus be seen that the invention provides a very simple, convenient and efficient machine for heating and handling workpieces; that the workpieces are fed to the front of and into the machine in a rapid and orderly manner; that the heating period is accurately timed; that the workpieces are pushed out of the furnace at the completion of a heating period, or in emergency at any stage of heating; and that the workpieces are removed laterally away from the front of the furnace after they have been returned therefrom.

While one embodiment of the invention has been described for purposes of illustration, it is to be understood that there may be various embodiments within the limits of: the prior art and the scope of the subjoined claims.

What is claimed is: v

1. In combination with an elongated tubular furnace chamber having a workpiece-receiving opening only slightly greater in dimension than the diameter of the workpiece to be heated, transfer means for removing a workpiece from the front, of the furnace chamber and for bringing another workpiece intoposition in front of the furnace chamber, a push-in device for pushing a workpiece into the furnace, a device for timing the duration of the heating period of the furnace while a workpiece is in the furnace chamber, a push-out device for ejecting a heated workpiece from the chamber, power means for r the workpiece, means actuated when the pushout device is in its rear position for starting said timing device into action, and means controlled by said timing device to halt the heating of a workpiece and to cause said push-out device to operate in an ejecting direction.

2. In combination with an elongated tubular induction coil heating furnace, a first pusher at one end of said furnace for feeding a workpiece into the furnace, a timer set into action by the feeding in of a workpiece for causing heatingcurrent to be supplied to the induction heating coil, a second pusher at the opposite end of said furnace set into action by the completion of a timed period by said timer for pushing a heated workpiece from thefurnace, the timer also cutting oif current to the furnace, transfer means set into action by completion of the action of pushing out a workpiece for removing a heated workpiece from the front of the furnace and placing another workpiece in feeding position in front of the furnacejand means actuated by said transfer means for causing said first pusher to operate after the transfer means has completed its movements. i P

3. In combination with an axially elongated heating chamber, guide means for directing a workpiece into the furnace along the axis, means for feeding a workpiece from said guide into the furnace and back on said guide means in front of the furnace, and transfer means for removing a returned workpiece laterally from said guide means and supplying a new workpiece thereto, said guide means including a V-shaped trough and means for tilting said trough to remove a returned workpiece and bringing it back to upright position to receive a new workpiece.

HAROLD A. STRICKLAND, JR. DONALD W. RIDDELL.

REFERENCES CITED The following references are of record in the file of this patent:

Number 15 Number 10 UNITED STATES PATENTS Name Date Wolfe Nov. 14, 1882 Hundley Oct. 10, 1899 Summey Feb. 25, 1930 Inscho Nov. 28, 1933 Strickland Aug. 3, 1943 Barkstrom et al. June 10, 1947 Unterweiser Apr. 27, 1948 Durand Mar. 22, 1949 Jagen Apr. 18, 1950 Journeaux May 2, 1950 FOREIGN PATENTS Country Date Great Britain Jan. 13, 1927 

